Abbreviated Name: ARVC

Disease Description: Arrhythmogenic right ventricular cardiomyopathy, also called Boxer cardiomyopathy or familial ventricular arrhythmias of Boxers, is a type of heart disease that causes an erratic and potentially unstable heartbeat (arrhythmia). 

Inherit Mode: The disorder is believed to be inherited as an autosomal dominant trait with variable penetrance, meaning it may be transmitted by the sire or the dam, and the extent to which offspring are affected is individually variable.  Males and females are affected equally.  No coat colour is associated with a higher or lower likelihood of developing arrhythmogenic right ventricular cardiomyopathy.

Disease Symptom: Arrhythmogenic right ventricular cardiomyopathy can be suspected in one of three different situations: 1- On a routine checkup, or during electrocardiographic (ECG) monitoring for anesthesia, the characteristic heartbeat irregularity is identified by the veterinarian; or 2- A dog develops episodes of stumbling, collapse, and/or loss of consciousness, and evaluation by the veterinarian reveals the typical cardiac arrhythmia on ECG; or 3- Arrhythmogenic right ventricular cardiomyopathy can be life-threatening, and occasionally there are no symptoms until a dog dies suddenly; an autopsy then identifies that arrhythmogenic right ventricular cardiomyopathy was the cause. Whether overt symptoms are present or not, arrhythmogenic right ventricular cardiomyopathy is a nonpainful type of heart condition that tends to worsen over time. Daily oral medications can be given at home to reduce the frequency and severity of symptoms if they are occurring, and dogs may live well for weeks, months, or occasionally years with arrhythmogenic right ventricular cardiomyopathy when they respond well to medications.

Disease Cause: -

Disease Diagnose: Arrhythmogenic right ventricular cardiomyopathy is confirmed using an electrocardiogram (ECG) to identify the characteristic irregular heartbeat (arrhythmia).  Since arrhythmias occur for many different reasons, standard blood and urine tests and medical screening (chest X-ray, ultrasound exam of the heart and the abdomen) are appropriate to identify other problems that are completely different but could be mimicking arrhythmogenic right ventricular cardiomyopathy.  In this way, arrhythmogenic right ventricular cardiomyopathy can be considered a diagnosis of exclusion: eliminating all other possibilities leaves it at the most likely remaining explanation.  Final confirmation is always possible at autopsy, where microscopic evaluation of the tissue of the right ventricle of the heart typically shows that it is infiltrated with abnormal fibrofatty tissue.

Treat Method: Arrhythmogenic right ventricular cardiomyopathy is a genetically-transmitted disorder and as such, the underlying cause cannot be reversed.  Medications are used for stabilizing the rhythm of the heartbeat (including such antiarrhythmics as sotalol, for example) and for offsetting some of the process of cardiomyopathy (such as with omega-3 fatty acids).  These treatments are oral medications that can be given at home, and a good response to treatment consists of a decrease or disappearance of symptoms.  The medications can provide a normal quality of life and this may continue for weeks, months, or occasionally years in dogs who respond well to treatment.

Breeder Advice: Boxers with arrhythmogenic right ventricular cardiomyopathy should not be bred.  Current standards include screening potential breeding stock using Holter monitoring; a specific cutoff remains elusive, but generally dog with <100 PVCs/24 hours are considered fit to breed and dogs with >1000 PVCs/24 hrs should not be bred.  The intermittent and highly variable nature of PVC occurence means that annual follow-up of beeding animals is very important, as is close evaluation of offspring if an adult later is found to have developed arrhythmogenic right ventricular cardiomyopathy after initially having been cleared on earlier screening.

Disease Description Source: Link